endo
New Member
Hi all AK'ers, thanks to a member on this forum 'HiFi in WYO' I am the proud owner of this tube amplifier: http://audiokarma.org/forums/showthread.php?t=634497
So far the amp has arrived, in great condition due to the seller packaging it so well he did such a good job. He double boxed and created a custom internal frame out of foam to support the amp and make sure it didn't move around and also bubble wrapped all the tubes and packed them out with bubble wrap.
The amp itself is in great condition for it's age, it's not perfect but very clean. All the RCA connections at the rear are shiny still, the lid has only a few minor marks. Really only thing is that the 2 top bass/treble knobs have some plastic that has broken off around the edge of the knob.
We believe this amp is pretty much identical so the SM-83(based on comparing it to the schematic), and there is also another variation SM-500. Some information is here on the SM-803: http://www.audiokarma.org/forums/showthread.php?p=6059903
It looks like this model was part of a specific Japanese console unit, why it has a lid on it ? not sure why it would need one when it's closed inside of a console.
A friend and I have put a new earthed 3 wire lead on, setup the power transformer to run on Australian 240v by putting the twin 115v windings in series. Replaced the 4 x ITT 1A silicon diodes that had been setup in place of the original bridge rectifier as one of them had gone closed circuit with a 10A 600V bridge rectifier.
We have been testing various components, using multimeter and this handy gadget he has leant me: http://www.ebay.com.au/itm/271597580019?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
The main electrolytic filter can cap's seem to test OK and have low ESR but this triple multisection 20uF 250V looks dodgy ? Does that look like it's burst it's guts where the rubber has oppened up and has maybe white electrolyte coming out ? The spot where im talking about is where the arrow is.
So far the wire wound resistors and ceramic resistors seem to be in spec still, any of the non-main filter caps all (Elna) electrolytics seem to test OK with the tester and have reasonably low ESR and are in spec but I am very suspicious about how they look and want to replace them ASAP.
The Suzuki paper in oil caps look OK, and test in spec but the ESR tests very high between 10-18Ohms respectively, would anyone have any more info about these ? Whether this is a normal value, or maybe this Hot328 meter can't properly detect that ? the same with the 50pf and 500pf mica capacitors, they seem to be in spec value wise but have a reading of 18Ohm ESR ?
Will be posting pictures and adding more information to this thread, any help or input is greatly value and appreciated.
Cheers,
-endo.
So far the amp has arrived, in great condition due to the seller packaging it so well he did such a good job. He double boxed and created a custom internal frame out of foam to support the amp and make sure it didn't move around and also bubble wrapped all the tubes and packed them out with bubble wrap.
The amp itself is in great condition for it's age, it's not perfect but very clean. All the RCA connections at the rear are shiny still, the lid has only a few minor marks. Really only thing is that the 2 top bass/treble knobs have some plastic that has broken off around the edge of the knob.
We believe this amp is pretty much identical so the SM-83(based on comparing it to the schematic), and there is also another variation SM-500. Some information is here on the SM-803: http://www.audiokarma.org/forums/showthread.php?p=6059903
It looks like this model was part of a specific Japanese console unit, why it has a lid on it ? not sure why it would need one when it's closed inside of a console.
A friend and I have put a new earthed 3 wire lead on, setup the power transformer to run on Australian 240v by putting the twin 115v windings in series. Replaced the 4 x ITT 1A silicon diodes that had been setup in place of the original bridge rectifier as one of them had gone closed circuit with a 10A 600V bridge rectifier.
We have been testing various components, using multimeter and this handy gadget he has leant me: http://www.ebay.com.au/itm/271597580019?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
The main electrolytic filter can cap's seem to test OK and have low ESR but this triple multisection 20uF 250V looks dodgy ? Does that look like it's burst it's guts where the rubber has oppened up and has maybe white electrolyte coming out ? The spot where im talking about is where the arrow is.
So far the wire wound resistors and ceramic resistors seem to be in spec still, any of the non-main filter caps all (Elna) electrolytics seem to test OK with the tester and have reasonably low ESR and are in spec but I am very suspicious about how they look and want to replace them ASAP.
The Suzuki paper in oil caps look OK, and test in spec but the ESR tests very high between 10-18Ohms respectively, would anyone have any more info about these ? Whether this is a normal value, or maybe this Hot328 meter can't properly detect that ? the same with the 50pf and 500pf mica capacitors, they seem to be in spec value wise but have a reading of 18Ohm ESR ?
Will be posting pictures and adding more information to this thread, any help or input is greatly value and appreciated.
Cheers,
-endo.
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